1. Field of the Invention
The present invention generally relates to devices for the protection of human hearing, and more particularly, to a hearing protection device that can be easily changed between a position which provides substantial hearing protection and a second position that permits more normal sound transmission.
2. Description of the Prior Art
Resilient foam ear plugs are widely used to provide hearing protection. These foam ear plugs are sometimes referred to as “self-adjustable.” The generally tubular foam earplug is compressed and inserted into the ear canal, where it expands and conforms to the ear canal. In its expanded position, this foam earplug provides a high level of hearing protection. The “foam” used in these ear plugs can constitute one of many possible soft resilient materials, including silicone, neoprene, polyvinyl chloride, polyurethane, and others.” These foam ear plugs are effective both as a result of the sound attenuation properties of the foam and the complete closure that results from expansion of the foam to contact the entire circumference of the ear canal. Thus it is important for the effectiveness of this ear plug that it remain firms positioned well within the ear canal in its expanded configuration.
Hearing protection is needed in situations such as firearm shooting activities in which there may be periods of loud noise followed by periods of no noise in which normal conversation is desirable. With prior art foam earplugs, however, conversation may be very difficult because of the high level of sound attenuation afforded by the ear plug. To permit more normal conversation the earplug must be removed, then re-compressed and reinserted into the ear canal before loud noises are again encountered. In addition, pressure differentials between the atmosphere and the inner ear resulting from the tight seal between the ear plug and the ear canal may be uncomfortable and may increase the user's desire to frequently remove the ear plug. Any situation in which a user's hands may become dirty (such as in handling a firearm or in an industrial workplace setting) the recompression of the earplug for reinsertion into the ear can result in contamination of the surface of the earplug and transfer of that contamination to the ear canal of the user.
Some hearing protection devices have attempted to selectively block certain sounds, such as the ear plug disclosed in U.S. Pat. No. 6,425,398, but with limited success. In many cases the effort to selectively block certain sounds results in less overall sound attenuation. No prior art hearing protection ear plug permits a user to physically switch the ear plug between a position in which substantial hearing protection is provided, to a position in which sound is only minimally obstructed and more normal conversation can take place.